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1.
《Chemical physics letters》2006,417(1-3):124-127
Laser-induced photo-catalytic degradation of phenol using WO3 was investigated for the first time. Effect of WO3 concentrations and laser energy on photo-catalytic removal of phenol from waste water was studied. Laser enhanced Photo-degradation can be an efficient method for the removal of phenol present in waste waters. The phenol removal process obeyed the first-order kinetics. 相似文献
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电化学氧化法去除苯酚研究 总被引:9,自引:0,他引:9
利用氯碱厂报废的DSA电极电解苯酚,结果显示:此电极对一定浓度的苯酚溶液有较好的去除效果.按影响电解效果各主要因素进行筛选,最佳实验条件为:电流密度30mA/cm2,pH10,支持电解质浓度10mg/L,苯酚浓度10mg/L.电解2h后,CODcr的去除率为66.7%,吸光度去除率为90%. 相似文献
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The development of an immobilized enzyme reactor (IMER) based on tyrosinase immobilized on aminopropyl-controlled pore glass (AP-CPG) for the removal of phenols from model aqueous solutions was reported. To elucidate the influence of the substrate nature, the apparent (V'max, K'm) and the inherent (Vmax, Km) Michaelis-Menten constants were determined by Lineweaver-Burk method and the external diffusional contributions on measured enzyme activities were removed by a graphical method. The dephenolization process was realized by recycling the phenol solutions through the bioreactor connected to a chitosan trap in order to remove the colored quinone-type products of the tyrosinase reactions. The results indicated that a complete removal of phenol derivatives in the range of 150-300 min, with the exception of 60% removal for phenol reached in 400 min, was obtained. The observed sequence: cresol > 4-methylcathecol > catechol > 4-Cl-phenol phenol was in accordance to the V'max/K'm values. 相似文献
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Bifunctional activated carbons (AC) with the abilities of both photocatalysis and adsorption were fabricated via the sol?Cgel route combined with hydrothermal treatment and N2 reactivation method. TiO2 was located mainly at the entrance of the surface macropores of AC. Under UV light irradiation, efficient removal of phenol was realized by combination of adsorption and photocatalytic degradation for the obtained bifunctional materials. In insufficient light or dark, phenol removal occurred mainly through adsorption. The prepared bifunctional carbon with a mass ratio of 50 TiO2 per AC ratio exhibited high efficiency for phenol removal. The total phenol removal capacity of 50TiO2/AC was almost 5 times of that of pure AC and 6 times of that pure TiO2 after 10 cycles. The prepared bifunctional carbons possess the advantages of high pollutant removal capability and good recyclability, making them promising for the efficient treatment of lightly polluted aqueous solutions. 相似文献
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Catalytic ozonation of phenolic wastewater with activated carbon fiber in a fluid bed reactor 总被引:2,自引:0,他引:2
The effect of activated carbon fiber (ACF) on the ozonation of phenol in water in a fluid bed reactor was investigated. It was observed that this combined process could increase the yield of the oxidation process significantly for phenol and COD (chemical oxygen demand) removal, especially for the phenol removal. The efficiency of ozonation increased with an increase in the dose of ACF. Higher initial phenol concentration only caused a slight decrease of phenol and COD removal. The results of repeated use found that ozonation could efficiently regenerate ACF in situ in the reactor, which was considered easy to handle without the costly ex situ regeneration of the industrial treatment process. The Boehm titrations and FTIR studies indicate that the ozonation process in water can significantly change the composition of acidic surface oxygen-containing groups of ACF, leading to the increase of carboxylic, hydroxylic, and carbonylic groups and the slight decrease of the lactonic groups. Furthermore, this process can also increase the surface area and total pore volume of ACF. Due to the new micropore formation and some pore enlargement, the micropores became smaller, and the mesopores and macropores got bigger. 相似文献
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The objective of this study is to remove the phenol from aqueous solution by using the neutralized red mud in batch adsorption technique. The study was carried out as functions of contact time, pH, initial phenol concentration, red mud dosage and effect of salt addition. The experiments demonstrated that maximum phenol removal was obtained in a wide pH range of 1-9 and it takes 10 h to attain equilibrium. The adsorption data was analyzed using the Langmuir and the Freundlich isotherm models and it was found that the Freundlich isotherm model represented the measured sorption data well. The influence of addition of salt on phenol removal depends on the relative affinity of the anions for the red mud surface and the relative concentrations of the anions. 相似文献
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In this study, graphitic solid core carbon nanorods (GSCNRs) were, for the first time, anchored to the surface of silica sands through the electron cyclotron resonance chemical vapor deposition method to provide coated silica sands as a new, low-cost, green, and efficient adsorbent for the removal of organic pollutants such as phenol and 2,4-dichlorophenol (2,4-DCP) from aqueous mediums. The characteristics of GSCNRs/SiO2 were confirmed through Fourier-transform infrared spectroscopy, X-ray diffraction, and scanning electron microscopy techniques. After the optimization of several parameters, the removal efficiency of phenol and 2,4-DCP using 1 g of adsorbent amount, the initial concentration of pollutants (10 mg/L phenol and 15 mg/L 2,4-DCP), a contact time of 10 min (phenol) and 20 min (2,4-DCP), and pH = 7 were 69 and 89%, respectively. The adsorption isotherm models of Langmuir and Freundlich, as well as pseudo-first-order and pseudo-second-order kinetic models, were examined under optimal conditions. Eventually, GSCNRs/SiO2 was regenerated five times for the removal of phenol and 2,4-DCP. The removal efficiency of the tested contaminants from inlet raw water of a water treatment plant using the proposed adsorbent was investigated. 相似文献
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Lead dioxide electrodes on Ti substrates were prepared by thermal-deposition or electro-deposition. The amount of hydroxyl radicals generated at the electrodes prepared by the above-mentioned two methods was compared with that at the electrodes mingled with Bi or La prepared by electro-deposition. The experimental results indicate that the highest concentration of hydroxyl radicals generated by thermal-deposition, electro-deposition mingled with nothing, electro-deposition mingled with Bi or La was 0.781, 1.048, 1.838 or 2.044 μmol/L, respectively. When phenol was electrolyzed on the four electrodes at a current density of 30 mA/cm2, the removal efficiency of phenol after electrolysis for 1.5 h was 87.30%, 93.55%, 97.95% or 98.70%, TOC removal efficiency after electrolysis for 5 h was 86.76%, 94.26%, 98.53% or 99.60%, respectively. Through the degradation experiments of phenol, the amount of hydroxyl radicals was responsible for the removal efficiency of phenol. The electro-catalytic characteristics were investigated by SEM, the generation amount of hydroxyl radicals, the degradation degree of phenol and the stability and conductivity of the electrodes were also investigated. The experimental results indicate that the four electrodes all show good electro-catalytic characteristics; the electro-catalytic characteristics of the electrode mingled with La were superior to those of the other three ones, and the electrochemical degradation of phenol followed one-step reaction dynamics. 相似文献
10.
Organoclays were synthesized by the ion exchange of cationic surfactants containing single, double and triple alkyl chains for sodium ions in an aqueous suspension of Wyoming Na-montmorillonite. The characterization of organoclays with and without adsorbed phenol was determined by X-ray diffraction, TEM and thermal analysis. Differences in the surfaces and in the interlayer of the mono, di and tri alkyl chain organoclays resulted in differences in the adsorption efficiency for phenol with tri > di > mono > Na-Mt. The results prove that organoclays can be effective for the removal of phenol from an aqueous solution and this removal is a function of the surfactant molecule and its concentration. In general, the higher the concentration as measured by the CEC value and the greater the number of alkyl chains in the surfactant molecule, the greater the percentage of the phenol that is removed. 相似文献
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Phenol removal from aqueous solution by adsorption and ion exchange mechanisms onto polymeric resins 总被引:1,自引:0,他引:1
Michelle Caetano Csar Valderrama Adriana Farran Jos Luis Cortina 《Journal of colloid and interface science》2009,338(2):402-409
The removal of phenol from aqueous solution was evaluated by using a nonfunctionalized hyper-cross-linked polymer Macronet MN200 and two ion exchange resins, Dowex XZ (strong anion exchange resin) and AuRIX 100 (weak anion exchange). Equilibrium experimental data were fitted to the Langmuir and Freundlich isotherms at different pHs. The Langmuir model describes successfully the phenol removal onto the three resins. The extent of the phenol adsorption was affected by the pH of the solution; thus, the nonfunctionalized resin reported the maximum loading adsorption under acidic conditions, where the molecular phenol form predominates. In contrast both ion exchange resins reported the maximum removal under alkaline conditions where the phenolate may be removed by a combined effect of both adsorption and ion exchange mechanisms. A theoretical model proposed in the literature was used to fit the experimental data and a double contribution was observed from the parameters obtained by the model. Kinetic experiments under different initial phenol concentrations and under the best pH conditions observed in the equilibrium experiments were performed. Two different models were used to define the controlling mechanism of the overall adsorption process: the homogeneous particle diffusion model and the shell progressive model fit the kinetic experimental data and determined the resin phase mechanism as the rate-limiting diffusion for the phenol removal. Resins charged after the kinetic experiments were further eluted by different methods. Desorption of nonfunctionalized resin was achieved by using the solution (50% v/v) of methanol/water with a recovery close to 90%. In the case of the ion exchange resins the desorption process was performed at different pHs and considering the effect of the competitive ion Cl−. The desorption processes were controlled by the ion exchange mechanism for Dowex XZ and AuRIX 100 resins; thus, no significant effect for the addition of Cl− under acidic conditions was observed, while under alkaline conditions the total recovery increased, specially for Dowex XZ resin. 相似文献
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A novel carbonized clinoptilolite-rich tuff was studied for phenol removal from water. Zeolite sample carbonization was accomplished
in a plasmachemical reactor (pyrolytic chamber) using several types of waste, here specifically waste vegetable residues and
starch. Phenol adsorption experiments were performed in the batch system. An industrial activated charcoal and a clinoptilolite-rich
tuff hydrofobized with an organic ammonium base were used as the related materials to compare phenol removal efficiency. 相似文献
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采用溶胶-凝胶法制备了不同管径的多壁碳纳米管-二氧化钛(MWCNTs—TiO2)催化剂.应用热重分析、N2等温吸附和BET比表面、X射线衍射、扫描电镜以及漫反射紫外可见吸收光谱等对样品进行了表征.选择光催化降解苯酚反应对光催化剂性能进行了测试,结果表明,MWCNTs—TiO2催化剂在苯酚降解反应中表现出明显的协同效应,并分别采用表观反应速率常数、总有机碳消除和光子效率对此协同效应进行了评价. 相似文献
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I. I. Vasil’eva T. N. Tyvina I. V. Dmitrieva 《Russian Journal of General Chemistry》2009,79(6):1361-1369
This paper presents structural relationships of phase equilibrium diagrams and azeotropic properties, and resulting evaluation of optimum process conditions for removal of hydroxyacetone (HA) and 2-methylbenzofuran (2-MBF) from phenol. It is demonstrated that the concentration region of HA separation from phenol is absolutely different from that for 2-MBF, which makes the task of HA and 2-MBF removal from phenol by distillation requiring installation of at least two highly selective extractive distillation columns operating with significant steam consumption. 相似文献
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Phenol is considered to be a priority pollutant due to its toxicity and carcinogenic effect. Thus, innovative and effective methods have been developed to remove undesired phenol from wastewater. Membrane processes are one of the innovative and effective methods used for the removal of phenol from wastewater. In this study, we investigate the effect of carbon and graphene oxide (GO) coating on phenol removal efficiencies of microfiltration, ultrafiltration, and nanofiltration membranes. Obtained results show the removal efficiencies of all membranes increase with rising pressure. Among all membranes, the carbon-coated nanofiltration membrane (NF90) showed the highest performance with a removal efficiency of 99% under a pressure of 6 bars. The physico-chemical properties of the coated and uncoated membranes were investigated by using Fourier transform infrared spectroscopy (FT-IR), scanning electron microscopy (SEM), X-ray diffraction and contact angle techniques (WCA). 相似文献
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Surfactants have been used to enhance the removal of phenol from aqueous system; therefore, the interaction between surfactants and phenol is important for selection of the surfactant and understanding the process. In this work, sugar based surfactant, n-dodecyl-beta-D-maltoside (DM), was utilized to separate phenol from aqueous solution using ultrafiltration. 2-D NMR and Cryo-TEM techniques were employed to obtain information on the orientation of phenol molecules in the micellar phase and the shape transition of the micelles. The flux was found to decrease linearly with the solute concentration and the equilibrium constant was found to be constant. 2-D NMR spectra have shown that phenol molecules reside in the palisade layer of the DM micelles with the benzene ring interacting with the hydrocarbon chain of DM molecules, especially the first methylene group. Cryo-TEM results have shown the shape transition from spherical to worm-like due to the presence of phenol. The results will help understand the interaction between surfactants and phenol and the select the optimum surfactant reagents and operational conditions for micellar enhanced ultrafiltration process. 相似文献
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effect of horseradish peroxidase (HRP) and H2O2 concentrations on the removal efficiency of phenol, defined as the percentage of phenol removed from solution as a function
of time, has been investigated. When phenol and H2O2 react with an approximately one-to-one stoichiometry, the phenol is almost completely precipitated within 10 min. The reaction
is inhibited at higher concentrations of H2O2. The removal efficiency increases with an increase in the concentration of HRP, but an increase in the time of treatment
cannot be used to offset the reduction in removal efficiency at low concentrations of the enzyme, because of inactivation
of the enzyme. One molecule of HRP is needed to remove approximately 1100 molecules of phenol when the reaction is conducted
at pH 8.0 and at ambient temperature. 相似文献